President Trump says he's determined to put an end to school shootings in the U.S. The president spoke at a White House news conference this afternoon with Malcolm Turnbull, the prime minister of Australia, a country that mounted its own successful crackdown on gun violence more than two decades ago. NPR's Scott Horsley reports.

SCOTT HORSLEY, BYLINE: President Trump says it's not enough to simply defend schools against gun violence. He wants to go on offense as well. Trump has proposed letting some school teachers carry concealed weapons in the classroom. He thinks that would deter would-be shooters like the one who killed 17 people at a Florida high school last week.

(SOUNDBITE OF ARCHIVED RECORDING)

PRESIDENT DONALD TRUMP: If, by the way, the bad guy thinks that somebody is in this room with a weapon that's going to be pointed at him with live bullets, he's not even going into the school. It's the one way you're going to solve it. You're not going to solve it with gun-free spaces.

HORSLEY: Trump criticized a sheriff's deputy who was outside the school in Parkland, Fla., while the shooting was underway inside. Trump's been asked if a trained deputy froze in the face of gunfire, how could teachers be expected to respond? The president argues armed teachers inside the school might be more effective than an armed guard outside.

(SOUNDBITE OF ARCHIVED RECORDING)

TRUMP: This man standing outside of the school the other day doesn't love the children, probably doesn't know the children. The teachers love their children. They love their pupils. They love their students.

HORSLEY: Mass shootings in Australia have been virtually non-existent since that country adopted sweeping gun control measures in response to a 1996 massacre. Speaking alongside Trump at the White House today, Prime Minister Malcolm Turnbull noted guns are much less common now in his country. But he adds Australia doesn't have a Second Amendment to consider.

(SOUNDBITE OF ARCHIVED RECORDING)

PRIME MINISTER MALCOLM TURNBULL: We are very satisfied with our laws. We maintain them, but we certainly don't presume to provide, you know, a policy or political advice on that matter here.

HORSLEY: The Trump administration has cast Australia as a cornerstone of what it calls the Indo-Pacific region, a counterweight to China along with India and Japan. Turnbull says this should not be viewed as a Cold War-style effort to keep China in check.

(SOUNDBITE OF ARCHIVED RECORDING)

TURNBULL: We see China's rise as being overwhelmingly a positive for the region and for the world. The critical thing, of course, is the rule of law is maintained.

HORSLEY: Some have questioned the U.S. commitment to the Asia-Pacific region after Trump pulled out of a big Pacific trade agreement. Australia and 10 other countries are moving forward with that deal. The Trump administration announced new sanctions today against shipping companies based in China, Singapore and Panama that have been secretly helping North Korea to evade international pressure on Pyongyang's nuclear program. Trump at first ducked a question of what might follow those sanctions, but eventually he offered an ominous warning.

(SOUNDBITE OF ARCHIVED RECORDING)

TRUMP: I don't think I would exactly play that card, but we'll have to see. If the sanctions don't work, we'll have to go phase two, and phase two may be a very rough thing. It may be very, very unfortunate for the world.

HORSLEY: Trump's daughter Ivanka is currently in South Korea for the closing ceremony of the Olympics. No meeting is planned with North Korea's representatives. Today is also the deadline when the president's son-in-law, Jared Kushner, and other White House staffers are set to lose their interim security clearances if they haven't passed a final background check. Trump defended the work Kushner has been doing on issues such as Middle East peace but said he would not overrule the directive on security clearances issued a week ago by his chief of staff, John Kelly.

(SOUNDBITE OF ARCHIVED RECORDING)

TRUMP: That will be up to General Kelly. General Kelly respects Jared a lot, and General Kelly will make that call. I won't make that call. I will let the general, who's right here, make that call.

HORSLEY: Trump says he's confident Kelly will do what's right for the country. The White House has said regardless of what happens with his security clearance, the president's son-in-law will continue his work. Scott Horsley, NPR News, the White House. Transcript provided by NPR, Copyright NPR.